The influence of purge flow parameters on heat transfer and film cooling in turbine center frames

Patrick R. Jagerhofer, Marios Patinios, Tobias Glasenapp, Emil Göttlich, Federica Farisco

Research output: Chapter in Book/Report/Conference proceedingConference paperpeer-review

Abstract

Due to stringent environmental legislation and increasing fuel costs, the efficiencies of modern turbofan engines have to be further improved. Commonly, this is facilitated by increasing the turbine inlet temperatures in excess of the melting point of the turbine components. This trend has reached a point where not only the high-pressure turbine has to be adequately cooled, but also components further downstream in the engine. Such a component is the turbine center frame (TCF), having a complex aerodynamic flow field that is also highly influenced by purgemainstream interactions. The purge air, being injected through the wheelspace cavities of the upstream high-pressure turbine, bears a significant cooling potential for the TCF. Despite this, fundamental knowledge of the influencing parameters on heat transfer and film cooling in the TCF is still missing. This paper examines the influence of purge-to-mainstream blowing ratio, purge-to-mainstream density ratio and purge flow swirl angle on the convective heat transfer coefficient and the film cooling effectiveness in the TCF. The experiments are conducted in a sector-cascade test rig specifically designed for such heat transfer studies using infrared thermography and tailor-made flexible heating foils with constant heat flux. The inlet flow is characterized by radially traversing a five-holeprobe. Three purge-to-mainstream blowing ratios and an additional no purge case are investigated. The purge flow is injected without swirl and also with engine-similar swirl angles. The purge swirl and blowing ratio significantly impact the magnitude and the spread of film cooling in the TCF. Increasing blowing ratios lead to an intensification of heat transfer. By cooling the purge flow, a moderate variation in purge-tomainstream density ratio is investigated, and the influence is found to be negligible.

Original languageEnglish
Title of host publicationHeat Transfer - Combustors; Film Cooling
PublisherAmerican Society of Mechanical Engineers (ASME)
ISBN (Electronic)9780791884973
DOIs
Publication statusPublished - 2021
EventASME Turbo Expo 2021: Turbomachinery Technical Conference and Exposition: GT 2021 - Virtual, Online, United States
Duration: 7 Jun 202111 Jun 2021

Publication series

NameProceedings of the ASME Turbo Expo
Volume5A-2021

Conference

ConferenceASME Turbo Expo 2021: Turbomachinery Technical Conference and Exposition
Country/TerritoryUnited States
CityVirtual, Online
Period7/06/2111/06/21

ASJC Scopus subject areas

  • Engineering(all)

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